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CN-121987861-A - Degradable coronary stent and preparation method thereof

CN121987861ACN 121987861 ACN121987861 ACN 121987861ACN-121987861-A

Abstract

The invention belongs to the technical field of arterial stents, and particularly relates to a degradable coronary stent and a preparation method thereof, wherein the degradable coronary stent is in a tubular network structure prepared from a main frame and connecting rib members, the main frame is in an open network structure, anchor points are arranged at nodes, the connecting rib members are detachably connected and locked with the main frame through the anchor points to form an integral rigid structure, the elastic retractive force after vascular implantation is effectively resisted, the vascular collapse is avoided, the connecting rib members gradually degrade and lose locking capacity along with vascular repair and advancing, rapamycin loaded by the connecting rib members is synchronously released, smooth muscle cells with active proliferation are accurately inhibited, the restenosis risk in the stent is reduced, and meanwhile, the main frame is restored to activity and slightly deformed along with vascular pulsation, so that the vascular intimal injury and inflammatory reaction are reduced.

Inventors

  • SHEN JINSHENG
  • JIANG YUFENG
  • XU HUI
  • Jiang Hezi
  • ZHOU YAFENG

Assignees

  • 苏州大学附属第四医院(苏州市独墅湖医院)

Dates

Publication Date
20260508
Application Date
20260311

Claims (6)

  1. 1. The degradable coronary artery stent is characterized in that a tubular network structure is prepared from a main frame and connecting rib members, wherein the main frame is of an open reticular structure and is provided with anchor points at nodes, the connecting rib members are detachably connected between the anchor points of the main frame and lock the reticular structure of the main frame into an integral rigid structure, and the degradation rate of the connecting rib members is faster than that of the main frame; The connecting rib component comprises the following raw materials in mass ratio of PLGA to HAP, wherein rapamycin=10:1-1.5:2-3; the preparation of the connecting rib component comprises the following steps: (1) Weighing PLGA, dissolving in dichloromethane to form PLGA solution, adding HAP into the PLGA solution, performing ultrasonic dispersion, then adding rapamycin into the PLGA solution, and magnetically stirring to form drug-loaded polymer solution; (2) Extruding the drug-carrying polymer solution to form a hollow composite microtubule, and vacuum drying the composite microtubule to obtain a solid composite drug-carrying microtubule; (3) Carving a preset connecting rib network pattern on the solid composite drug-carrying microtube, cleaning, and drying in vacuum to obtain the connecting rib component.
  2. 2. The degradable coronary stent of claim 1, wherein in step (1), the ratio of PLGA to dichloromethane is 1 g:8-10 mL.
  3. 3. The degradable coronary artery stent of claim 1, wherein the main framework is prepared from PLLA, and the preparation method of the main framework comprises the following steps: (a) Extruding PLLA to obtain a PLLA preformed pipe, and biaxially stretching to obtain the PLLA pipe; (b) Carving diamond grid patterns on the PLLA pipe, carving anchor points at grid crossing nodes to form a PLLA component; (c) And ultrasonically cleaning the PLLA component, and drying in vacuum to obtain the main frame.
  4. 4. A method for the preparation of a degradable coronary stent according to any one of claims 1-3, comprising the specific preparation steps of: S1, precisely embedding a connecting rib member between anchor points of a main frame to form an assembly, and performing thermal fusion, cooling and demoulding on the assembly to obtain a bracket matrix; S2, weighing CD47 peptide, dissolving in a mixed solvent of dimethyl sulfoxide and water, performing vortex oscillation to enable the CD47 peptide to be fully dissolved to form an inner shaft liquid, weighing PCL, dissolving in a mixed solution of chloroform and ethyl acetate, and performing magnetic stirring until the PCL is fully dissolved to form an outer shaft liquid; and S3, carrying out coaxial electrostatic spraying on the stent matrix, carrying out vacuum drying to form a composite stent, carrying out oxygen plasma treatment on the composite stent, and carrying out low-temperature sterilization to obtain the degradable coronary stent.
  5. 5. The method for preparing the degradable coronary stent according to claim 4, wherein in the step S2, the dosage ratio of the CD47 peptide to the mixed solvent is 1g to 10mL, the volume ratio of the dimethyl sulfoxide to the water is 1 to 1, the dosage ratio of the PCL to the mixed solution is 1-1.5 to 20 mL, and the volume ratio of the chloroform to the ethyl acetate is 3 to 1.
  6. 6. The method according to claim 4, wherein in the step S3, the parameters of the coaxial electrostatic spraying are set to be that the flow rate of the inner shaft liquid is 0.1-0.3 mL/min, the flow rate of the outer shaft liquid is 0.5 mL/min, the spraying voltage is 10-20 kV, and the spraying distance is 10-15 cm.

Description

Degradable coronary stent and preparation method thereof Technical Field The invention belongs to the technical field of arterial stents, and particularly relates to a degradable coronary arterial stent and a preparation method thereof. Background The main treatment means of coronary atherosclerotic heart disease (coronary heart disease) is percutaneous coronary intervention, and a stent is implanted to open a narrow blood vessel and restore blood flow, so that the prognosis of a patient is obviously improved. However, the development of stent technology always faces the core contradiction of supporting effectiveness and vascular repair compatibility, and the existing stent still has a plurality of technical pain points to be solved urgently. Although the metal bare stent applied in early clinic can realize vascular expansion, vascular intimal smooth muscle cells are easy to excessively proliferate after implantation, restenosis in the stent is easy to be initiated, and the drug-coated metal stent can reduce restenosis, easily initiate chronic inflammatory reaction and increase the risk of thrombus in the late stent. As a new generation of technology, degradable stents need to provide support during the vascular repair period (6-12 months) and then degrade and absorb. The prior art still has various limitations that the traditional degradable polymer stent (such as a pure PLA stent) is difficult to combine the requirements of high initial support and low later stimulation, and the degradation rate of the ferroalloy is slow, but degradation products are easy to locally gather, so that oxidative stress or inflammatory reaction can be initiated. The existing degradable medicine bracket releases medicine and the blood vessel repair stage is disjointed. For example, part of stents are coated with antiproliferative drugs directly on the stent surface, which can inhibit smooth muscle proliferation at the initial stage, but the drugs are easy to fall off due to blood flow scouring, so that release is uneven, therefore, development of a novel degradable coronary stent capable of realizing 'initial high-rigidity support, medium-rigidity self-adaptive reduction and drug time-series release' is needed, and the coronary heart disease interventional therapy technology is promoted to develop towards safer and more effective directions. Disclosure of Invention The invention provides a degradable coronary artery stent and a preparation method thereof, wherein the main frame and the connecting rib component are prepared into a tubular network structure, the main frame is provided with an open network structure, the connecting rib component is detachably connected and locked with the main frame through the anchor points, so that an integral rigid structure is formed, the elastic retractive force after vascular implantation can be effectively resisted, the vascular collapse is avoided, the connecting rib component is gradually degraded and loses locking capacity along with vascular repair and advancing, the main frame recovers a certain mobility, the integral rigidity is reduced along with the gradual deformation of the vascular pulsation, the continuous mechanical compression on the vascular wall entering a repair stage is avoided, and the vascular intimal injury and inflammatory reaction are reduced. Early in vascular repair, rapamycin is released synchronously along with PLGA hydrolysis in the degradation process of the connecting rib component, so that the risk of restenosis in the stent is reduced from the source. When the blood vessel enters the middle and later stages of repair, the connecting rib component is basically degraded, the PCL layer on the surface of the main frame is gradually exposed and slowly releases the CD47 peptide, the adhesion and proliferation of endothelial cells are efficiently guided, the complete coverage of the blood vessel intima is accelerated, and the adhesion and thrombus of blood platelets are reduced. The degradable coronary artery stent prepared by the invention solves the problems of insufficient support at the initial stage, collapse easiness, unbalanced support adaptation of the injured blood vessel with excessively strong rigidity at the later stage and high risk of restenosis in the stent. The invention provides a degradable coronary artery stent, which is prepared from a main frame and a connecting rib member into a tubular network structure, wherein the main frame is of an open reticular structure and is provided with anchor points at nodes, the connecting rib member is detachably connected between the anchor points of the main frame and locks the reticular structure of the main frame into an integral rigid structure; the connecting rib component comprises the following raw materials in mass ratio of PLGA (polylactic acid-glycolic acid copolymer) to HAP (nano hydroxyapatite) to rapamycin=10:1-1.5:2-3; the preparation of the connecting rib component comprises the following steps: (